Having made a few poses with Firestorm's Poser facility, I uploaded the resulting .bvh files to SL. During the upload preview, regardless of what priority I chose, the preview showed that there was interference by whatever standing animation was active - either my AO's or the default LL standing animations. This behaviour continued even after I've uploaded the pose, as the title suggests. I reproduced this behaviour with both Firestorm 7.1.13.78266 and the current version of the official viewer, which I downloaded and installed to be sure. I also tested by reuploading .bvh poses I had created with AnyPose - these were NOT affected. To be clear: in all cases I set my uploaded poses to priority 4.